In recent years, there have been a larger number of examples where camera modules that fulfill their automatic focusing functions by means of lens drive devices are mounted in electronic devices such as mobile phones. The lens drive devices are commercially available as various types such as types in which stepping motors are used, types in which piezoelectric elements are used, and VCM (voice coil motor) types.
In the case of fixing of lenses to such a lens drive device, the initial position of the lenses with respect to an image pickup element along the optical axis must be set accurately; otherwise, an out-of-focus image will result from defocusing. Further, in a fixed-focus camera module, whose lenses are not moved, the initial position of the lenses can be made more highly accurate by mounting the lenses or a lens holder holing the lenses directly in the image pickup element or a member holding the image pickup element (e.g., see Patent Literature 1).
Citation List
Patent Literature 1    Japanese Patent Application Publication, Tokukai, No. 2003-046825 A (Publication Date: Feb. 14, 2003)
Patent Literature 2    Japanese Patent Application Publication, Tokukai, No. 2008-197313 A (Publication Date: Aug. 28, 2008)